The continued growth of the Internet in combination with demands for new services is rapidly increasing the requirements imposed on network systems, such as IP routers. The basic functions of an IP router can be divided into two main components: the forwarding plane (also referred to as the data plane) and the control plane. These components, while inter-related, perform functions that are largely independent of each other. The forwarding plane is generally responsible for a router's capacity to process and forward packets, which may include functions such as packet forwarding (also referred to as packet switching), which is the act of receiving packets on the router's interfaces and usually sending them out on other interfaces; classification; traffic shaping; and metering. The control plane is generally responsible for controlling the router. The control plane implements functions such as routing protocols, signaling protocols, control protocols (e.g., RIP, OSPF, and RSVP), and network management and dictates the forwarding behavior by manipulating forwarding tables, per-flow QoS tables, and access control lists. For example, the control plane gathers and maintains network topology information and passes this information to the forwarding plane so that the forwarding plane knows where to forward received packets. Typically, the architecture of these two components combines all of the required functionality into a single functional whole with respect to external entities. The increasing requirements put on network systems, such as IP routers, require new protocols in the routers, leading to an increased complexity in the control plane and frequently involve and affect the communication between the forwarding plane and the control plane.